To test the influence of local (county) politics on minority incarceration rates. Data are collected at the county level in California to create a pooled cross-sectional data set. OLS regression models predicting black, Hispanic, and white incarceration rates (in state prison) are used in the analysis. Counties' ideological orientations and racial and ethnic contextual characteristics significantly impact minority incarceration rates. Greater ideological conservatism within counties is associated with higher rates (as a proportion of their population) of both black and Hispanic incarceration. Consistent with racial threat theory, results show counties with greater racial and ethnic diversity are more likely to incarcerate blacks and Hispanics. Tests for interaction effects indicate that greater county diversity decreases the punitive effects of ideological conservatism on minority incarceration. Political forces nested within states systematically shape how state government incarceration power is distributed across different racial and ethnic groups.